Budidaya tanaman cabai besar mempunyai resiko tinggi akibat adanya serangan penyakit. Tujuan penelitian ini yaitu untuk mengetahui jenis cendawan patogen yang menginfeksi tanaman cabai besar di Kelurahan Juata Laut. Penelitian ini dilaksanakan di lahan budidaya tanaman cabai besar dan di laboratorium perlindungan tanaman Universitas Borneo Tarakan. Pengambilan sampel menggunakan metode accidental sampling. Isolasi menggunakan metode tanam langsung dengan cara membersihkan permukaan buah dan daun menggunakan NaOCl 1% dan alkohol 70%, kemudian dibilas dengan akuades steril dan dipotong seukuran 1 cm2 kemudian ditanam pada media PDA. Setelah tumbuh, cendawan diidentifikasi mikroskopis dan makroskopis. Ditemukan 3 patogen pada tanaman cabai besar yaitu Fusarium sp, Colletotrichum sp dan Cercospora sp.
Kata Kunci: Cabai Besar, Fusarium sp., Colletotrichum sp., Cercospora sp.

Cultivation of chili plants (Capsicum annum L.) has a high risk due to disease attacks. The purpose of this study was to determine the type of pathogenic fungi that infected the chili plants in Juata Laut Village. This research was conducted in chili cultivation areas in the Universitas Borneo Tarakan plant protection laboratory. Sampling was done using accidental sampling method. Isolation was carried out using a direct planting method by cleaning the surface of the fruit and leaves using 1% NaOCl and 70% alcohol, then rinsed with sterile distilled water and cut into 1 cm2 size then planted on PDA media. After growing, the fungi were identified microscopically and macroscopically. Three pathogens were found in the chili plants, namely Fusarium sp, Colletotrichum sp and Cercospora sp. Keywords: Chili, Fusarium sp., Colletotrichum sp., Cercospora sp.